Dealing with Mobility: Understanding access anytime, anywhere

15 Pages·2001·0.1 MB·English

by  Mark Perry

Dealing with Mobility: Understanding access anytime,
anywhere
MARK PERRY†, KENTON O’HARAˆ, ABIGAIL SELLEN‡, BARRY BROWN‡ AND RICHARD HARPER∞
†Dept. of Information Systems & Computing, Brunel University, UK
ˆ The Appliance Studio, Bristol, UK
‡Hewlett-Packard Laboratories, Bristol, UK
∞Digital Worlds Research Centre, Surrey University, UK
ABSTRACT
The rapid and accelerating move towards the adoption and use of mobile technologies has increasingly provided people and
organisations with the ability to work away from the office and on the move. The new ways of working afforded by these
technologies are often characterised in terms of access to information and people ‘anytime, anywhere’. This paper presents a
study of mobile workers that highlights different facets of access to remote people and information, and different facets of
anytime, anywhere. Four key factors in mobile work are identified from the study: the role of planning, working in ‘dead time’,
accessing remote technological and informational resources, and monitoring the activities of remote colleagues. By reflecting on
these issues, we can better understand the role of technology and artefact use in mobile work and identify the opportunities for the
development of appropriate technological solutions to support mobile workers.
KEYWORDS
Mobile technology, mobile workers, mobile communication, awareness, distributed collaboration, diary study, interviews,
information access, anytime, anywhere.
MOBILE WORK, MOBILE TECHNOLOGY
The rapid and accelerating move towards the adoption and use of mobile technologies has provided people and organisations with
the ability to work in novel and previously unanticipated ways. Such developments are at both the level of emerging technological
infrastructures for connectivity (e.g. WAP, Bluetooth, Sun’s Jini, and HP’s JetSend, location pinpointing technologies, 3G and
GPRS) and mobile information appliances such as mobile phones, personal digital assistants (PDAs), and laptop computers. These
have the potential of provoking even more radical changes in work practices and encourage an even greater level of mobile work
and distributed collaboration.
Mobile work differs in many interesting ways from desk work. It can also present the business traveller with a unique set of
difficulties. When people work in an office, they have greater familiarity and certainty about the environment and resources (i.e.
technologies, information, documents and people) available to hand. People in offices know where technologies such as the
photocopier and the fax machine are and that their personal equipment is set up appropriately for their work environment. They
structure the information and documents around them to suit their needs and they know who to ask for particular kinds of
information. Such familiarity with their environment affords them greater freedom over the way they organise their work. Of
course, systems break down and technology can go awry, but in general, when people work at their office desks, they know how
to go about fixing their problems, and finding what they need to perform the job at hand.
Contrast this resource-rich view of office work with the difficulties encountered by a mobile worker on a business trip who may
experience a range of different contexts both in transit and at their final destination. Such contexts (e.g. clients’ offices, hotel
rooms, airports and vehicles such as trains, aircraft and cars) are likely to be more unfamiliar to the mobile worker in terms of
factors such as available technology and communication infrastructures, available workspace and noise levels (Lamming et al.,
2000). In addition, they do not have the access to colleagues or knowledge of who to seek to get support. The greater
unpredictability - or heterogeneity (Kristofferson and Ljungberg, 1999) - of the contextual constraints within which mobile work
must take place means that they have less control over the configuration of their environment and therefore the way that they
manage their work.
In light of the particular difficulties encountered by mobile workers, one of the major premises of mobile technologies is to
remove the bindings between a fixed space and a person’s information and communication resources. By supporting access to
these resources wherever they go, the argument is that uncertainty associated with the contextual constraints encountered while
mobile is removed. This is intended to give back control to the mobile worker over when and where they can do their work. As a
rhetorical device for the promotion and selling of mobile technologies, the “access, anytime, anywhere” construct serves an
important function. However, in terms of understanding technology use in mobile work and informing design through this
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understanding, such a construct may not be quite so useful since it misrepresents the reality of the difficulties faced by mobile
workers. Indeed, as other authors have argued (e.g. Churchill and Wakeford, 2001), this and other rhetorical devices used in the
mobile technology industry “contribute to a common discourse of mobility” from which narratives of use are drawn. These
narratives embody a set of simplistic assumptions about the nature of mobile work. In the absence of a real understanding of what
constitutes mobile work, these narratives are the only fallback in justifying and shaping design decisions.
As Luff and Heath (1998) have shown, misunderstanding the nature of mobile work can be problematic and can lead to
technologies being used in unexpected ways. For example, they describe a situation in which a mobile device was introduced onto
a building site to replace a paper allocation sheet used to record the amount of time that workers were spending on particular
aspects of the job. The system was supposed to provide a mobile resource for the foremen as they wandered round the site to help
them monitor problems as they were encountered and to support in situ discussions with other people on the site. What happened
in actual use, however, differed from the intent of the designers. Instead of being used as a communication tool in support of the
mobility of the foreman around the site, it was primarily used as a data documentation device. That is not to say that it failed as a
useful tool, but merely that it was not useful for its intended support of mobile work practice. This occurred because the device
actually impeded certain important features of the collaborative work practices of the foremen and the other workers when out on
the site. For example, with the existing paper-based version of the allocation sheets, there would be a brief hand-over of
documents and a simultaneous discussion about the problems on site. During these discussions, the paper documents would be
dynamically positioned to render them “accessible” to the participants as the needs of the conversation dictated. With the new
electronic mobile system, the characteristics of the device, such as its size, shape and screen intensity made it difficult for such
subtle shifts of “accessibility” of information between collaborating participants. In practice, then, the system actually hindered
mobile collaboration rather than supported it.
In response to some of these issues, what we set out to do in this paper is contribute to a deeper clarification of the rhetorical
underpinnings of mobile work. In particular, rather than treating the three concepts of access, anytime, anywhere as monolithic
terms, we intend to argue that each of these terms is multifaceted in meaning with each facet having different implications for the
way in which we think about mobile work and the technologies designed to support it.
As an illustration, one simply has to look at one of the primary purposes of mobility itself. That is, one of the main reasons for
being mobile is to have face-to-face interactions with others (e.g. Bellotti and Bly, 1996; Lamming et al 2000; Henning and
Bragen, 1994). It is well established that face-to-face access to colleagues is different and usually much richer than remote
collaboration through technology. There are thus different kinds of access to other people and one needs to look carefully at
whether new technologies can deliver the necessary support for the task at hand. Similarly, if we look at access to documents and
information, again, different kinds of tasks require different kinds of access. For example, the kind of access required to be able to
exchange a document as an email attachment is different from the level of access necessary to allow editing of the document. In
the first instance one does not really require visual access to the contents of the document but merely access to the digital
information that encodes the document such that these bits can be emailed onwards1. In the editing instance, one requires visual
access to a modifiable document.
To illustrate the notion of “anywhere” in the same way, we can see that accessing or transporting documents between a desktop
computer in an office and a laptop in a hotel room constitutes a different level of spatial granularity than the “anywhere”
associated with Luff and Heath’s (1998) micromobility of documents and artefacts (the small shifts in position and orientation
configurations of artefacts in response to the ongoing demands of a particular task). The granularity differences in spatial shifts in
these two examples demands a different set of affordances from the information embodiments used to support them. So the laptop
is able to receive a document anywhere that a network connection can be established with the computer back at the office. But
once the document is received, the laptop cannot be spatially reoriented at the micro level, for example during a face to face
interaction, in the kind of ways that a paper embodiment of the same document would allow (e.g. Luff, Heath, and Greatbatch,
1992; Harper and Sellen, 1995). This notion of “anywhere” also assumes a geometric notion of space, in which all places are
assumed to be functionally equivalent. We can also look at the social facets of “anywhere” and consider spaces in terms of the
different properties and social norms governing the kinds of activities that can take place there. For example, the kind of mobile
phone conversation one can have in a public place surrounded by others is different from the kind of conversation could have in a
different place with no one else around (cf. Churchill and Wakeford, 2001). In this instance, anywhere access is possible, but may
not be acceptable.
Finally, as an illustration of the notion of “anytime” let us consider the task of writing a document on a laptop while needing to
reference some information from a source document. The level of time granularity associated with a quick glance access of
information from a paper document located adjacent to the laptop is very different from the time granularity associated with
getting exactly the same information by pulling the document over the Internet. The different embodiments of the information in
these two instances offer very different values and properties in terms of the way they can be drawn upon as a resource for the

1 It is recognised that one might want visual access to the document for the purposes of confirming that the correct document is
being attached and sent. For the purposes of this illustration, this is not important and so is not included.
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ongoing activities. To ignore these different facets is to ignore the very features of the competitive artefact ecology within which
new mobile devices must operate. As with notions of space assumed in the rhetoric of “anywhere”, the notion of “anytime” often
assumes a linear notion of time. This is as opposed to the facet of “anytime” characterised by the social norms and properties of
time that affect information access and communication behaviours. For example, many people might consider it inappropriate to
make a phone call about work-related issues outside a mutually agreed understanding of “work time”.
In this paper then, we present a user study of mobile workers on business travel in order to further unpack what it means to be
mobile and to work in different places at different times. We hope to learn from observation of how they currently use the
resources they have to hand to think systematically about what they might need in the future. For example, we hope to be in a
better position to answer important emerging design questions such as how and why should wireless communications be
incorporated into mobile devices (such as PDAs)? What new data services might be useful to access via mobile phones? What
document handling facilities should be incorporated into mobile devices? In addition to informing new design directions for
mobile technologies, it is also about developing an understanding into the rationalities of use of existing artefacts in real world
practice from which we can begin to infer how emerging technologies will compete for use in the ecology of existing
communication and information artefacts.
PREVIOUS RESEARCH
Much of the research on mobility has dealt with technology issues such as limited battery life, unreliable network connections,
varying channel coding, volatile access points, risk of data loss, portability and location discovery (Wiberg and Ljungberg, 1999).
However, as a number of authors have commented, user centred research of collaborative mobile work is now beginning to
emerge as an important field in its own right (e.g. Luff and Heath, 1998; Bergqvist et al, 1999). There is now a growing number
of studies of mobility in collaboration offering observations and findings about the actualities of mobile work. Some of the
findings can be recast to inform our particular concerns about “access, anytime, anywhere” and form the foundations on which
observations from our own study of mobile work can build.
In one of the earlier studies of its kind in the area, Whittaker et al. (1994) carried out an in-depth shadowing study of 2 mobile
professionals. One of them was primarily mobile within the local office environment, the other was mobile both within the local
office, but also remotely (within the local metropolitan area). The primary focus of their work was on the informal
communication activities of these people rather than mobility per se, but they also looked at the role mobility served in enabling
access to colleagues for these interactions. This occurred through the chance encounters with colleagues that mobility facilitated
such as bumping into someone while roaming, as well as more planned visits to the offices of others. This extent of this mobility
away from the desktop led to difficulties in being able to access colleagues successfully (two thirds of attempted phone calls failed
because the other person was not at their desk). The study also highlighted how different spatial locations varied in terms of the
perceived intrusiveness associated with them. For example, in “on the move” serendipitous informal interactions, the caller is not
interrupting the recipient in the same way as when calling on them at their office. The subtly different social properties of these
spaces influence the duration of the collaborative activities.
Local mobility (defined as within easy walking distance of their office space, walking between rooms or buildings at a local site)
is further examined in an ethnographic field study of a distributed design team by Bellotti and Bly (1996). The particular theme of
the study was how this local mobility was important in supporting communication and awareness activities highlighting the
importance of collocating with a colleague to get a richer level of access than would be possible using telecommunication from the
desktop. The mobility also gave a certain level of access to colleagues that provided people with awareness of what was going on
elsewhere in the workplace. However, one negative consequence of this local mobility was that, as in the Whittaker study,
telephone access by remote colleagues was made more difficult.
Awareness and communication are also discussed in Luff and Heath’s mobility studies (1998). One example they discuss comes
from their observations of staff and management at the London Underground. In this case, many of the information and
communication resources that were required for them to perform their work were located in the Ops room. When a member of
staff was mobile and away from this room, they were unable to access the ongoing changes taking place in it: they no longer had
continuous visual and auditory access to colleagues and information such as inadvertently overhearing activities in conversations
and phone calls. The access to this information was ongoing and unplanned when in the Ops room - one cannot predict the time
when a particular piece of eavesdropping will become an important resource for a particular work activity. The form of access
that many mobile technologies (such as mobile phones) provide is not equivalent to the access allowed by being in the Ops room,
since this kind of remote access must be deliberately initiated.
As we have discussed earlier, Luff and Heath’s (1998) paper talks not just about the mobility of people but also the mobility of
artefacts (micromobility) and the way they are ongoingly configured within collaborative activity. By articulating examples of
these different configurational needs, they point to some of the different facets of “access”, “anytime” and “anywhere” that we are
addressing in this paper. In particular they discuss how the properties of different forms of representations of the same
information impact on micromobility. For example, when talking about the role of documents in mobile conversations (cf.
Whittaker et al., 1994) they point to the ecological flexibility of paper in this role compared with conventional computer systems
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or even laptops which are regarded as “cumbersome and rigid” in terms of how they can be used during conversation.
The role of documents and access to documents in mobile work is further developed in a series of studies by Eldridge et al, (2000)
and Lamming, et al. (2000). These studies examined situations involving mobility both within the local area and beyond the
metropolitan area using a variety of quantitative and qualitative approaches to data collection. These studies are important in
characterising some of the particular features and problems of mobile work such as the unfamiliar nature of the environments in
which people often find themselves, the unanticipated nature of document activities, the difficulties in “accessing” remote
documents and the frequency of face-to-face interactions in which paper documents play a key role (cf Luff and Heath, 1998).
The findings from these studies are used to inform the design of a new system called Satchel. The Satchel system allows
document tokens to be carried round on a mobile device. When these tokens are instantiated, for example by beaming them to
another device (e.g. a Satchel enabled printer), the actual document is pulled across the Internet to the recipient device. Some of
the design features of the Satchel system are clearly based on the need to think about different facets of information access. For
example, they talk about the need to beam a document token to a printer to create access to the document appropriate for face-to-
face interaction. This they regard as different to the type of access necessary simply to beam a document token to another mobile
device.
With regard to unpacking the concepts of anytime and anywhere in the Satchel papers, there is less discussion but there is an
important point to be raised here. Many of the features of the Satchel system are dependent on place and time being defined by
the presence of Satchel enabled devices. This is not a criticism of Satchel per se, whose value has been demonstrated through
extensive field trials (e.g. Lamming et al, 2000), but is intended as a vehicle for illustrating the different features of different
places - defined by the technological ecology of that space. These issues perhaps become more apparent if we consider some
findings from O’Hara et al (2001) regarding the relationships between the mobile phone conversations of mobile professionals and
their document activities. For example, one participant from the study was driving his car and received a phone call regarding
some information on a spreadsheet on the caller’s PC in the office. While the caller was able to give a certain level of “access” to
the information by verbally describing it to the driver, the driver really needed visual access to the document to truly engage in the
conversation. The point here is that while a mobile technology could allow access to the necessary document by having it
transmitted to the mobile phone in the car, this would not be suitable for the situation at hand. Additional technology would be
necessary to allow the appropriate level of visual access to the document contents. In this particular situation, the characteristics
of the place (the car) were such that this additional technology was not available - therefore “access” here was not possible.
Similarly, if we consider the particular time when the person received the phone call, the ongoing activity of driving meant that
visual inspection of a document would be dangerous anyway.
Lack of awareness of recipient activities and features of time and place which impact on type of access possibilities can lead to
disruptions in what Churchill and Wakeford (2001) call the ‘reciprocity’ and ‘rhythm’ of collaborative interactions between
mobile workers and colleagues. Reliable rhythms, they argue, are necessary to establish for ongoing collaboration to work
effectively. The breakdown in the reliability caused by the particular difficulties of mobile work and technological problems they
observed can lead to the subsequent abandonment of particular communication and collaboration media for mobile workers. In
relation to these issues, their fieldwork also points to the problems caused by the functional asymmetries between devices that
purport to allow access anytime, anywhere. For example, they talk about access asymmetries between emails sent from a desktop
machine to a mobile device. The mobile device was restricted in terms of its ability to view attachments as well as its ability to
have access to the embedded hyperlink URLs. Sender expectations were such that the email had been read with all the same
levels of access available at the desktop. This not being the case there were mismatches in rhythm expectations leading to
problems in ongoing collaborative activity.
A core component of mobile work is travelling. Wiberg and Ljungberg’s (1999) ethnographic study of mobile telecommunication
engineers in Sweden examined how the work they did was dependent on both time and place. Their results show that travelling
could not easily be avoided because of the places that they had to visit physically, such as telephone poles, network routers,
locations where new cables needed to be drawn, as well as customers’ homes and non-mobile customers. The timeframe that the
work had to be conducted in was also often not negotiable, as, for example, customer service had to be dealt with within 24 hours
or rebooting parts of the telephone network had to be done at night. Another important finding from the study was the problem of
knowledge sharing amongst the technicians. Since they worked alone in their cars most of the day, they faced a very real problem
of finding out about ongoing developments in other projects. The authors conclude that the practical limitations of the structure of
their work made it impossible for the mobile service engineers to conduct knowledge sharing “anytime, anywhere”. Whether this
is the case for other types of mobile workers is debatable, but an examination of these issues is long overdue if we are to design
really effective mobile technologies.
What we see in these studies is a move toward examining the nature of mobile work. However, this research area is still not
populated with a large enough corpus of information to undertake any kind of theory building. The area is further complicated by
the increasing adoption of new technologies and organisational work practices. Nevertheless, understanding the nature of the
problems that mobile workers face and their artful use of the resources that they have access to can provide a rich resource to
designers in scoping the design space that they will need to work within. The purpose of the current study is therefore to further
understand the nature of mobile work by looking at mobile workers’ activities carried out before, during and after business travel.
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Within this study of mobile workers in situ, we focus on how these workers manage information through documents and through
mobile communication technology.
METHOD
From previous work, such as segmentation studies of mobile professionals (e.g. Ablondi & Elliott, 1993) it is evident there is great
diversity in the nature of the work that mobile workers do, their modes of travel, and their document and technology use. We
therefore felt it important to recruit a sample of mobile workers that were representative of these differences. To do this, 17 mobile
workers from the UK were chosen from a range of different professions. Participants were pre-screened to represent different
levels of mobility in terms of typical duration of business trips (overnight, day), distance travelled (e.g. within local area, national,
international), type of transport (e.g. plane, train, car) and the extent to which they worked collaboratively. Professions included a
variety of management personnel from a range of industries, sales staff, consultants, medical workers, civil servants, and the
media. For a summary of the participants, their roles, resources and patterns of mobility, see Table 1.
We were particularly keen to represent frequent air travellers to destinations outside the UK as well as regular road or train
travellers moving within the local area and other parts of the country. For this reason, we did not examine working from home (as
a form of mobile work). All participants bar three worked in different organisations. The relatively small number of participants
selected meant that we could afford to explore the rich details of their activities, using interviews in which they were able to show
us the resources that they had described and sometimes even demonstrate their use. The study was not designed to provide a
complete survey of mobile behaviour but rather was intended to be interpretive, rather than statistical. Thus we will not discuss
statistics or frequency data here, but will examine use-practices and situated activities.
In order to collect rich and detailed information about the interviewees and their work practices, we felt it was important to gather
many different kinds of situated data, and to gain our understanding, as far as possible, from observation and interviews in the
actual work settings of these individuals. This would involve gathering a comprehensive set of data covering the full range of
communication and document activities that these mobile workers were engaged in. Interviews alone will not suffice, as people
are necessarily selective in what they describe or think is important to discuss. The solution to this involved using a combination
of diary techniques, interviews, and analysis of the artefacts (technologies and documents) used during specific business trips.
This grounded the study in real activities and provided a means of unearthing the detailed contextual backdrop of the participants’
information and communication activities.
We decided the best way to gather grounded data was to plan our interviews around actual business trips, both before and after
these trips. In this way, we hoped to gain a longer term understanding of what happened during travel – from the kinds of
preparations made prior to travel, to the minutiae of what actually took place over the whole travel episode. This helped to give a
deeper understanding of the context surrounding the mobile workers’ activities. Each participant was therefore interviewed twice.
To aid the contextual nature of the interview and to support the interpretation of the data, where possible, interviews were
conducted in the participants’ usual (static, i.e. non-mobile) workspaces; these were located in and around London and Bristol
over three months in mid 1999. Approximately 43 hours of interviews was conducted in all; these were tape-recorded and later
transcribed. Where appropriate, artefacts were also photographed. A follow-up study was conducted between November 2000 and
Feb 2001 to see how patterns of activity had changed in the meantime; this examined another five mobile workers from the same
profile in terms of their mobility. This involved a single one and a half hour interview following a business trip (similar to the
second interview of the primary study). No major differences were noted in their behaviour and use of technology other than in
their increased use of text messaging for personal reasons, most usually for co-ordinating meeting locations and for playful
messages. Their data is not included in this report as it did not involve the full interview schedule, and as such they are not directly
comparable, although it is interesting to note that after one and a half years, very little has changed in the activity patterns of
mobile workers.
A first interview prior to the trip helped to inform us about the context surrounding the mobile workers’ activities - why they
travelled and what preparations they were making for the trip, who they would be seeing and what they would be taking with
them. This was conducted as close as possible prior to the departure date for the next upcoming business trip, in the majority of
cases, 2 working days or less before the trip (cancelled trips making up the remainder). The interview was around an hour long,
and its purpose was to build up a general background about the nature of the participant’s work and their home life. We explicitly
asked questions regarding their position and responsibilities in the workplace, who they worked with and the nature and frequency
of this collaboration; we then asked for descriptions of ‘typical’ days, so that we were aware of the difference between their office
and travel based activities. We asked further information about the frequency and type of typical travel that they undertook. So
that we could understand their information, communicational and technological requirements, we asked about their family and
social networks, existing technology infrastructure at home and office and the availability of, and technologies used whilst they
were mobile. The participants were then asked questions specifically relating to the upcoming business trip. This included the
purpose of the trip, the duration of the trip, where they were going and whom they were expecting to meet. In terms of information
and communications activities, we enquired about the kinds of information they were expecting to pick up over the travel episode,
the preparations that they would have to perform before travelling, such as planning presentations (e.g. photocopying, MS
PowerPoint slide creation), preparing documents to take with them (and why). Finally, we enquired what technologies they would
be taking with them (and why). At the end of the interview, the participants were asked to bring any materials (e.g. emails, paper,
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and electronic documents) generated or collected while away to the second interview.
A second interview was carried out as soon as possible after the trip (again, for the majority of interviewees, within 2 days of
returning) and was based around the schedule of events that had taken place on the trip in terms of their information use and
communications activities. This lasted about an hour and a half on average. In this respect, our approach allowed us to ground the
study in real activities and to use the trip diaries and existing artefacts to unearth the detailed context of their document and
communication. We began the interviews by focusing on an overview of what had happened during the whole trip. The
participants were then asked to identify a typical day in the trip to unpack in more detail. This ‘typical’ day was determined in
concert with the interviewee: this allowed the participant themselves to highlight the everyday nature of their work, rather than the
interviewers picking unusual episodes. A schedule was then constructed of this whole day from waking to sleeping, framed in
terms of their travel, informational and communications related activities.
The participants brought material that they had generated or collected during the trip to this interview and these were discussed in
relation to their activities, goals and motivations. They were asked what they planned to do with these artefacts after returning.
This formed the basis for discussing the use and purpose of these artefacts (with respect to their activities, goals and motivations).
To support the data collection and its subsequent analysis, during the interviews, a document and communications inventory was
taken. The document inventory involved the compilation of a list of the information used by the participant prior to their travel
episode, during the diary day, and during the rest of the trip. (e.g. text, document, scribble, sound, scene), how it was acquired or
produced, and how it was (or was expected to be) used. For example, this included activities such as reading it, distributing it to
another person, storing it for later use, and so on. The communications inventory recorded the communication episodes (for
example, phone calls, email, and fax use fax) during the diary day, the purpose and nature of this communication, and subsequent
use of information from the communication. The inventories collected in these interviews allowed us to investigate the extent to
which documents were used in conjunction with communication episodes in the analysis. In a final set of questions, the
participants were asked if they had experienced any particular problems in relation to their document-related and communication
activities while travelling – these too were recorded in an inventory.
FINDINGS
Unsurprisingly, there was great diversity in the nature of mobile working by the 17 people in this study and in the ways in which
they appropriated the tools they had to hand to accomplish their work. Even the notion of ‘mobile work’ itself was diverse. The
participants in this study were mobile in many different ways, echoing the findings of Dahlbom and Ljungberg (1998). They
worked at multiple (but stationary) locations, they walked around a central location, they travelled between locations, worked in
hotel rooms, worked on moving vehicles, and worked in remote meeting rooms. Participants described their activities involving
some or all of these types of “mobile” work, with each having its own particularities, constraints and sets of resources.
Rather than consider each of these kinds of work in turn, we sought to try to identify any common themes or features of behaviour
that bound them together. Here we found four sets of key findings about the way in which mobile technologies (both “high tech”
devices such as mobile phones, and “low tech” artefacts such as paper) were used by mobile workers to maximise flexibility in
their ways of working and access to information while on the move. These issues can be summarised as follows:
∑ Preparing for a trip and planning for the unpredictable (“planful opportunism”)
∑ How mobile workers effectively made use of “dead time”
∑ Use of the mobile phone as a “device proxy”
∑ Use of technologies for remote awareness monitoring
These four topics explore key notions of resource and task flexibility, how mobile workers make effective use of their time, how
they maintain awareness about remote activities, and how they are able to access remote information and devices. While other
authors have discussed some of these findings in some form or another, what we attempt to do here is to explore the issues
surrounding them. We demonstrate how these activities are used in supporting the performance of mobile work and the ways in
which they are interdependent and intertwined both with and within other activities. We will consider each key finding in turn in
the sections that follow.
Planning Opportunistic Access to Information
As we have indicated, one of the characteristic difficulties of mobile work is that there is less predictability and more restricted
access to information and artefacts in the environments encountered. One of the important features of mobile workers then
concerns the ways in which they deal with this through planning activities prior to the trip to make sure that they can use the
information when and where it is required. One may interpret this as appearing somewhat paradoxical in the sense that planning
can be argued to be ill-suited to unpredictable circumstances. However, this would be to overload our use of the word planning.
Rather, what we mean is that in order to be able to flexibly adapt to the situation, mobile workers had to be prepared to generate
workarounds through ad hoc activities developed in concert with the resources that they were able to co-opt at the time. When
people know that they are going to encounter situations in which they cannot know exactly what is required of them, they can plan
for this by collecting together and carrying particular technologies, documents and resources. We call this ‘planful opportunism’,
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in contrast to ‘opportunistic planning’ (Hayes Roth and Hayes Roth, 1979) in which people make plans ‘on the hoof’ reacting to
circumstances as they are experienced.
This planning activity centred on making sure that documents and information would be available in the appropriate form when
and where they would be needed. Much of the trip planning behaviour centred on participants collecting together paper documents
in a project, or trip, file. Files on particular topics (for example, client records) were printed out, photocopied or collected from
filing cabinets. Having them in paper form allowed them to be collated together in a common format to be taken on a journey and
then their contents selected from and configured as the situation at the remote site developed. In a quote from one of the
participants, there is a clear requirement to take paper documentation for use in different situations:
“So there’s about a dozen folders in plastic wallets on my desk and I’ll probably be taking about three of them in their current
form and probably another one which has sort of components of two or three of those other wallets. So I’m going over with
information in my hand…“
The reasons for gathering together paper into a single format file was that paper has important characteristics (e.g. Harper and
Sellen, 1995) that make it useful for opportunistic appropriation by the mobile worker in a range of circumstances both predictable
and unpredictable. The planned activity and context of use was important in decisions of where, when and how the information
was going to be used. For example, in mobile meeting situations, small amounts of paper were portable enough to be taken to the
meeting, immediately viewable for ad hoc reference and referral as required. This permitted them to distribute the documents
2
among others for use there and then , and afforded a high level of micromobility (Luff and Heath, 1998) within the meeting space
that made it a useful conversational resource. Likewise, paper was frequently used for ad hoc reading activities, as illustrated by
the number of participants who printed documents out or carried paper documents specifically to read if they experienced any
spare time and had to work in places where they could not do other types of work (because of a lack of resources). The use of
paper was ecologically flexible and thus by choosing it as a medium, the participants knew that it could be accessed in contexts
where other technologies would be awkward to use. This ecological flexibility meant that carrying paper was perceived as a
reliable option. Paper use was not hindered by the complications of technology infrastructure incompatibility or breakdown, and as
such it was sometimes carried as a backup of electronic documents.
Planful opportunism was also seen with digital technologies with some particularly elaborate strategies being employed to ensure
that access to the information in different places and different times would be in the appropriate forms for use. As the following
extract from a project manager in an e-business department illustrates, these combined media strategies also highlight the kinds of
perceived potential breakdowns in the access to and use of information by the mobile worker:
“…I’ll be sending out the slide set which will drive the meeting next Thursday. My feeling is that I’ll have good access to cc mail
once I’m over there but I may not access to the other information that is on the shared drive…. I’ll be moving round from one desk
to another and that my experience is that I can’t actually log on as myself over in another county because it messes up all the NT
settings on the other person’s PC so the best I can do is log on to my cc mail on their PC.… I’ve asked if I can have a lap-top
during the week just so that if I do need to any work in the evenings and I have that capability…. What I’ll do is I’ll probably
[take] a diskette over with me too with the most important documents and just so that I know that I’ve actually got the information,
the electronic information with me. Particularly the slide set you know, the most important documents, I’ll probably take both in
paper form and electronically because my design session I’ll want to be using the electronic version rather than the paper
version.… I’ve e-mailed myself with all my bookmarks so that if I need to get hold of a URL during the week and I can’t remember
was it on e-mail or did I stumble across it or whatever then I can go into just one e-mail message knowing that the attached file
contains all my bookmarks…. I even e-mail myself at home as well so that if I need to do any work in the evening then I’ve got the
right documents there, electronically sent to me.…”
What this example shows is that the level of uncertainty associated with mobile work and the different forms in which information
is both delivered and carried to make it accessible in the right form, in the range of places where it will be used, for a range of
different tasks. This participant was unsure as to whether he could take a laptop, was unsure about whether there would be
sufficient email reliability both in the hotel room and the office he was visiting. What was interesting was that having the ability to
send information electronically did not exclude the need to take it on paper.
One of the subjects commented that the laptop and mobile phone provided him with the ability to access unanticipated documents
either from the hard drive or via mobile phone connectivity and thereby reduced the need for some of the pre-planning activities.
This is indeed an important potential benefit of the mobile technologies and illustrates an interesting relationship between the need
for pre-planning and the flexibility provided by mobile technologies. However, what was additionally interesting about this was
that in reality, the participant also carried various paper documents, some of which were available electronically on his laptop,

2 ‘Permitted’ in the sense that no common technological infrastructure was assumed for exchange, although conversely, they were also restricted
because multiple copies might be required for ad hoc distribution, in which case paper can be less flexible than electronic documents.
7
should he have needed them. This also applied to a number of the other participants with laptops. There were various reasons
given for this: for example, the possibility that these paper documents would be used as an impromptu conversational resource in
meeting situations, or for reading whilst travelling. The point here is that if a document was needed for a discussion it would be to
hand in paper form, and paper was regarded as being more appropriate to the context of this unanticipated use.
Planning behaviour, then, was not simply about what documents were needed but also in what form they were needed to allow
appropriate access on the trip. Laptops for example did not support the same type of impromptu document access as paper for
various reasons despite the fact that in theory they offered the potential flexibility to open unanticipated documents from the hard
3
disk or over a network connection. First, laptops were not generally regarded as ‘casual use or carry devices’ . Impromptu
information retrieval via connected laptops was hindered by the fact that laptops themselves were subject to planning decisions
about whether or not to be taken. While approximately 70% of the participants had a laptop that they could take with them, only
about half of these actually took them on the trips we studied (most of these cases involved an overnight stay). Furthermore, taking
a laptop on a trip did not necessarily imply that it would then be subsequently taken into meetings. What is important about this is
that this form of laptop carrying behaviour conflicts with its potential use to support unanticipated document and communication
needs.
Working in Dead Time
While it was possible to talk about the purposes of business trips, the nature of work undertaken during these trips was highly
varied. The work carried out cannot be usefully characterised simply in terms of the specific work purposes of the trip, such as the
need to meet face to face with a client to discuss something. To do so would be to ignore the large amounts of time outside the
scheduled activities of a trip characterising much of business travel. This time was described by participants as “dead” time,
“travel” time, “spare” time or “wasted” time. The common factor was that this time occurred between tasks and between meetings,
usually in which the participants had little control over the resources they had to hand. Work in this ‘dead time’ would take place
in a variety of locations (e.g. cars, trains, buses, aeroplanes, hotel rooms, airports and office buildings), each placing a range of
different constraints on the information artefacts that could be used and the kind of work that could therefore be done. Examples
of this included time spent in transit, or waiting for travel, such as in airport lounges or railway stations. Where the participants
knew that they would have periods of dead time to fill, they would often plan ahead to make good use of it:
“On a completely dead day like I had on Wednesday, I can check some Voice mail, check some e-mail but otherwise have an
uninterrupted, quiet day in my hotel room. I can just focus. I spent a lot of time sorting loads of notes in my bag. Sorting it in to
stuff I could file. This was stuff I had taken away with me. Before l left I knew the Wednesday was going to be clear so my
briefcase was full of all these notes I had accumulated and never prioritised the time in order to rationalise them and get them
sorted. “
In addition, many of the business trips described by the study participants were characterised by multiple meetings or activities
that were scheduled to exploit the fact of being in a particular location or within the vicinity (saving time, money and effort). The
accounts manager for the brewery, for example, had a management meeting one day, and decided to stay overnight rather than
return home because she had a training meeting next day in the same part of the country. This need for her to stay overnight
created a period of dead time in the evening. Likewise, many of the overseas trips were characterised by multiple meetings spread
over several days (to take advantage of having travelled that distance) with long periods of time between meetings.
The need to work in dead time was recognised as being increasingly important for those engaged in mobile work to help manage
the build-up of tasks that occurs while they are mobile. If the workers wait until they return to complete these tasks, they will have
a heavy backlog of work to catch up with. Working in dead time allows them to distribute some of this build-up of workload over
the time spent away from the office:
“It's convenience, to keep on top of it, because if you don't, it will be full and be completely out of control by the time you come
back.… Travelling is just part of the job as opposed to a rare event. I'm travelling 2 or 3 times a month so it’s part of the job.
Staying in touch is important, both from a management of the workload perspective, to make sure there's not this enormous pile,
and secondly to be in touch if there is anything that comes up that needs a quick response.”
From a design perspective, being explicit about how dead time is used is important because it appears to be a key element of
mobile work with its own distinct characteristics. For example, it is very different from the kinds of activities and contexts in
which the more scheduled, face-to-face activities occur during business travel. This can have implications for understanding the
different levels of information access that are required or possible in particular situations and places where the mobile worker
finds they have some dead time. For example, for those participants who spent time in cars, the only real work that was possible
was based around the use of the mobile phone, hands-free or otherwise. Access to information and documents in these instances is

3
The level of casualness varied among participants. One of the subjects, for example, who had a laptop and a mobile phone, downloaded his
email at the airport while waiting for his flight.
8
not limited just by technology but by the limitations of human information processing (cognitive loading, attention, memory, etc.)
and the physical inability to read and process document-related information while driving.
The exact form that dead time takes for mobile workers can be difficult to characterise because of the range of circumstances
under which it occurs. There is a huge variety for example in the different time scales involved with certain types of dead time.
For example, the time period of a break in a meeting is different from the time spent in a hotel room, and the utilisation of time in
a particular situation requires a particular resource and technology set. Taking advantage of short time periods between meetings
or during meeting breaks was conducive to doing work such as making a phone call or checking voice mail on the mobile phone.
Here we found that activities were rarely organised according to priority or urgency. Rather, work was organised according to the
context where dead time was experienced and the resources available to hand, such as mobile technologies and artefacts, the work
being ‘fitted in’ as, and when, it could be done. The ecological flexibility of a technology was therefore an important part of this
type of activity, the mobile phone and paper being particularly useful in supporting this kind of work in giving access to a variety
of resources. As one of the participants discussed in their use of the mobile phone to access voicemail:
“It's more accessible because you can do it from far more places geographically than you can e-mail - car, airport lounges, home,
as opposed to which e-mail needs to be in the office most of the time. It's also quicker both to connect and to listen to and to
respond to.”
When time permitted, a few of the participants who used laptops would also use them during this dead time for checking their
email or, very occasionally, creating new documents. As the following example illustrates, a participant took advantage of the fact
that there was a delay with his flight that provided him with an appropriate length of time to engage in some ‘email activity’. What
is interesting to this discussion is the way that this was done: he had utilised a period of dead time in the hotel room to access his
email, downloading it to his laptop - but not reading it. This allowed him the flexibility to exploit the delay time at the airport by
providing immediate access to read and write responses to these emails.
“Called to see if I could get hold of my wife to say hello, wasn’t there, left a message on voice mail and then headed off to LA and
sure enough the flight was delayed so sat in the airport and worked and got through some of those e-mails that had been piling up
that I hadn’t been able to get to…Just basically took my laptop out.”
Other types of dead time were less constrained by time availability and more by the environment, in terms of physical and network
resource availability. For example, dead time on the plane was often utilised by participants to read paper documents. This was
partly because of the ease of use of paper (as noted above), but also because many of the participants liked to use (and planned for)
this uninterruptible time for a certain type of quiet, reflective reading and annotation. In addition, the constraints on the space
available can impact on the type of work that can be done to make use of this time and therefore the level of document access that
was required. For one of the participants, the work that he would do with a laptop would generally require access to other
documents to view and refer to them while manipulating an electronic document on the laptop. The fact that he could not use his
laptop and simultaneously access documents from his briefcase meant that he had to restrict this work in dead time to reading
paper documents:
“I read a few things on the plane. I don't use laptop on plane. In the back of the plane there is not enough room to use a laptop
and have access to your briefcase.”
The notion of dead time is a problematic one and is difficult to pin down. We have made use of it because it is analytically useful,
but also because it was a frequently used category by the participants themselves. What makes it hard to define is its fragility:
mobile workers actually make use of this time, so it is not strictly unusable in terms of the actions that can be conducted within it.
Rather, when they expect to spend a period of time out of communications or without the full set of resources to do the work that
they would ordinarily have, the participants made use of devices and preparation strategies to (at least partially) revive this time.
In practice, however, we found dead time was rarely used as efficiently as it could be. Here then lies a challenge for developers: to
design devices and services to allow mobile workers to make full use of dead time taking into account the diversity of
environments in which it occurs and the paucity of resources often available.
Phone as a Device Proxy
One of the main uncertainties that emerged in the mobile work we studied was when and where people would have access to
technologies and documents necessary to do particular aspects of their work (for example, a fax machine or an email connection).
As it happened, helping to deal with or work around these uncertainties turned out to be a key value of the mobile phone. The
flexibility of the mobile phone (in terms of where it could be used and its use in problem solving discussions) allowed participants
to be able to access equipment and documents back home or at another location by proxy. For example, one of the participants was
in his car where he had an hour of dead time available. He therefore made a phone call to a customer using his mobile about some
equipment for he was trying to sell. While he was able to give them enough overview information to get them interested, the
customer wanted full written details to peruse before they would commit to buying. Here, the phone call was not sufficient in itself
9
to make the sale because the customer needed time to look through the details more closely and in his own time. There was
therefore a need to support the verbal communication with some form of paper-based visual information to meet the customer’s
needs. The solution to this was to fax this information to the customer in support of the phone call. However, the participant did
not have access to a fax in the car and nor did he have access to the information in a document at hand. He therefore made a call
on his mobile phone to his office requesting that they find the necessary document and fax the full details to the customer.
This example is interesting because the participant did not have access (in the sense of being able to forward the information on to
the client) to the information necessary to complete the demands of the phone call. Predicting the need for taking the document
was not possible because of the ad hoc nature of the phone call during what was otherwise dead time in the car. As such, not only
was the technology not available to send the fax but neither was the document. So while a mobile faxing device could have been
useful in situations like these, this must be interpreted within the context that the mobile worker will often not have the
information they want to be able to compose the fax.
Other examples of the use of the phone as a device proxy include it being used to dictate letters and to access and respond to
emails:
“… I could ring up the office normally and speak to my secretary, she does shorthand and she can type it as quick as I can say
over my mobile ‘phone, you know, letter to so and so, really urgent, must go out, dear Mr so and so reference our conversation, I
have pleasure in quoting you for this blah, blah, blah, that’s the price Linda, you know, and she’ll end and whatever It, and I’ll
say nip in my drawer and get the technical information, get it in the post this afternoon, he’s really chasing it. You know, that sort
of thing happens but I can do that on the ‘phone. I can do most things verbally.”
In another instance, one participant had phoned his office when he was unable to connect remotely to get someone there to log into
his email account and read aloud any emails that he had received. He then dictated his replies over the phone and they typed this
up and sent it off as an email. However, although the telephone can act as a device proxy, it is not always the ideal task for the job:
“…I mean I use a mobile telephone probably because I haven’t got a mobile fax, it would be nicer for me because I find myself
ringing up one person in the office and I might ring him up ten minutes later to say I’d forgotten something so if I could sort of
you know during the day jot down everything I had to tell one person in the office and send off a fax then you’ve also got the
written record and so it’s safer.”
Whilst it may not be the perfect tool, the phone allows the mobile worker to achieve their important goals without having to place
a high degree of effort in locating or carrying around specialised information or communication appliances with them. In this
respect, the mobile phone provides a workaround to help reconstitute some of the resources normally available to the office
worker in a flexible manner as and when the needs arise, by allowing their operation from a remote location, if not by directly
operating them remotely. The mobile workers therefore do not need to carry their offices with them, but do carry the means by
which they can access (at least a degree of) their functionality.
Remote Awareness Monitoring and Access to Colleagues
Maintaining informal awareness of what is going on in the office and building a sense of community are important features of
work. Evidence of this is seen in the workplace design literature (e.g. Tanis and Duffy, 1999) and in studies of informal
communication (Heath and Luff, 1991; Whittaker et al. 1994). In the office, information that may or may not be useful to the
worker is picked up incidentally throughout the course of a normal work day, through, for example, bumping into people in the
corridor or being interrupted by someone needing to speak to you.
One of the problems faced by mobile workers away from the office is how to maintain this informal awareness of what is going on
back in the office and also how to maintain a sense of community at work. Mobile technologies can potentially help to support
these aspects of work. In the study we saw some evidence of this. For those who took laptops on business travel, these workers
were able to maintain some sense of connectivity with the workplace through email. However, email activity was typically
performed at the end of the day in a hotel room, when there was time to download it, and when network access was available.
Use of the laptop (and thus access to email) was also much more infrequent than that of the mobile phone. For many of the study
participants, the inability to access email anytime and thus maintain a connection to their offices was partially ameliorated by
using their mobile telephones to ‘touch base’, and keep ‘up-to-date’ with developments at work whilst away. They found it useful
to phone the office “just in case” anything urgent arose so that they could monitor developments. They also used the mobile
telephone to keep abreast of general contextual issues that could impact on their understanding of situations and therefore, on their
job. This was important not just for dealing with issues whilst away, but also to help with the catch-up period on returning to the
office.
In practice, obtaining this information was not always a matter of urgency, and it was performed at convenient points during the
day to support their awareness of what was going on at the periphery of their current tasks. The kind of information they required
10